They had a nice run, but flip and feature phones are well on their way to becoming endangered species.

Smartphones are more popular than ever, making up a slim majority of total mobile phone sales, according to new data from Gartner. During the third quarter of 2013 (3Q13), smartphones "reached their highest share to date" with 55 percent of all mobile phone sales, said the research group.

Worldwide, buyers snapped up 250.2 million smartphones during 3Q13, a whopping 45.8 percent gain from the same period a year ago. In total, vendors sold 455.6 million phones during 3Q13, a 5.7 percent year-over-year gain. Gartner predicts that overall mobile phone sales will reach 1.81 billion units this year, an increase of 3.4 percent over 2012.

Gartner's Anshul Gupta, a principal research analyst, noted that feature phone sales "continued to decline and the decrease was more pronounced in markets where the average selling price (ASP) for feature phones was much closer to the ASP affordable smartphones."

As a result, demand for feature phones is cratering in China and Latin America, where "users rushed to replace their old models with smartphones." In Asia-Pacific, the smartphone segment notched a hefty 77.3 percent increase.

In some markets, the biggest threat to smartphones is mini tablets, suggested Gupta. "We will see several new tablets enter the market for the holiday season, and we expect consumers in mature markets will favor the purchase of smaller-sized tablets over the replacement of their older smartphones."

Smaller slates (generally 8 inches and below) are fueling the current the tablet craze. Earlier this year, IDC revised its 2013 worldwide tablet forecast from 172.4 million units to 190.9 million based on the growing demand for devices like the Apple iPad mini, Google Nexus 7 and Amazon Kindle Fire.

Android is the most popular smartphone operating system (OS) by far. Google's mobile OS powered 205 million smartphones sold during 3Q13 and accounted for 81.9 percent of the smartphone market. Apple iOS captured 12.1 percent of the market on sales of 30 million iPhones.

"However, the winner of this quarter is Microsoft, which grew 123 percent," stated Gupta. The software giant, which is in the process of acquiring Nokia's handset business, picked up 3.6 percent of the market with 8.9 million Windows Phone devices sold.

Samsung is the smartphone vendor to beat with sales of 80.3 million units and 32.1 percent of the market. Apple ranked second with 12.1 percent and Chinese PC maker Lenovo followed with a 5.1 percent share of the market.

Pedro Hernandez is a contributing editor at Datamation. Follow him on Twitter @ecoINSITE.